1. Field of the Invention
The invention relates to a power steering apparatus for assisting steering through torque generated by an electric motor or a hydraulic pressure generated by an oil pump driven by the electric motor.
2. Description of Related Arts
Conventionally, a power steering apparatus that confers a steering assisting force according to a steering manipulation to a steering mechanism has been employed to assist steering. Such a power steering apparatus includes, for example, an electric type in which torque generated by an electric motor is conferred to the steering mechanism as a steering assisting force, and an electro-hydraulic pump type in which an oil pump is driven by an electric motor to feed hydraulic fluid to a power cylinder from the oil pump, and toque generated by the power cylinder is conferred to the steering mechanism as a steering assisting force.
Incidentally, in some of vehicles to be scrapped due to an accident or expiration of the life of an engine, an electric motor or an electronic control unit for controlling the driving of the electric motor remains usable in a steering apparatus mounted on the vehicle. However, a degree of deterioration with use to date is uncertain, and therefore, the remaining usage time cannot be estimated, which makes it impossible to reuse the electric motor or the electronic control unit collected from a vehicle to be scrapped.